Equine lameness has many causes, of which laminitis is among the most serious. Laminitis, often called founder, is a disease that affects fifteen (15) percent of the horse population and results in debilitation in nearly seventy-five (75) percent of those horses. Despite recent intensive investigation, no cure currently exists, but early detection and prompt treatment can, in most cases, prevent the need for euthanasia. Laminitis is a fast acting disease that attacks and breaks down the connective tissue, the laminae, between the horse's hoof wall and coffin bone. The disease occurs in three successive stages: the developmental, the acute, and the chronic. The developmental stage of laminitis occurs between initiation of the disease and the appearance of acute lameness and lasts a maximum of seventy-two (72) hours. The acute stage can last between four (4) and sixty (60) hours. This means that many horses may be already in the chronic stage of the disease before they receive treatment. Therefore, until an actual cure is found, a feasible method for preventing and treating the disease is needed.
While a cure for laminitis may be in the distant future, recent research on the use of cryotherapy (or cold therapy) as a potential prophylactic offers immediate hope for preventing the disease. Two landmark studies from the Australian Equine Laminitis Research Unit have opened this area of research. Pollitt and Van Eps ((Pollitt, C. C. and Van Eps, A. W. Prolonged, continuous distal limb cryotherapy in the horse. Equine Vet. J. 2004; 36(3): 216-220) initially evaluated the effect of prolonged, continuous cryotherapy to the equine distal limb. They found that continuous cryotherapy was well tolerated and resulted in a marked cooling of the treated foot. In a subsequent study Van Eps and Pollitt determined that distal limb cryotherapy could be used to prevent laminitis induced by alimentary carbohydrate overload. (Van Eps, A. W. and Pollitt, C. C. Equine laminitis: cryotherapy reduces the severity of the acute lesion. Equine Vet. J. 2004; 36(3): 255-260) their results suggest that cryotherapy could be used as a potentially effective prophylactic strategy in horses at risk of developing acute laminitis. Even though cryotherapy has been shown to be a potentially effective strategy, the method used, icing down the horse's leg, is both cumbersome and imprecise. Furthermore, researchers have previously only used cryotherapy on one leg of the test animals for a short time.
It is also known that the application of a vacuum to an injured member, especially together with cryotherapy, is also beneficial in increasing blood flow and, thereby, in healing. Cold therapy applied with reduced pressure has been shown effective in rapidly reducing core temperature of human and animals and in improving performance. Reducing core temperature is useful in treating overheated individuals but has also been shown to increase performance, as is done with athletes. See, for example, U.S. Pat. No. 6,656,208 U.S. Pat. No. 6,156,208 and the references and other patents sited therein. See also products of and information provided by AVAcore Technologies, Inc., 333 Parkland Plaza Drive, Ste. 700, Ann Arbor, Mich. 48103, 333 Parkland Plaza Drive, Ste. 700,
Subjecting an injured member to a magnetic field is another technique known to promote healing and prevent soreness. See U.S. Pat. No. 4,587,956, U.S. Pat. No. 6,139,486 and U.S. Pat. No. 6,062,008. These therapies lead to enhanced comfort for horses when being transported and stalled as well relieving and/or preventing development laminitis and related diseases in equine animals. The present invention provides a greatly improved apparatus and method for cryotherapy for animal, especially equine animals.